Columbia University alumni are blasting football coach Pete Mangurian’s strategy to slim down his offensive line — a twist on the usual strategy of beefing up blockers.

“You might think this is a wimpy Ivy League thing, but you can’t do that on any level of college football,” said Jake Novak, a ’92 alumnus who runs the fan blog Roar Lions 2013. “We are very much the lightest O-line team in the Ivies, and this is by design,” he added. “It’s not working.”

The Lions went 0-10 this season for the first time in 26 years, and critics say the slim-fast program has much to do with the humiliating skid.

The linemen averaged 262 pounds at the end of the season — compared to Princeton’s 284 pounds and Dartmouth’s 282, according to the teams’ rosters.

Some players are as much as 40 pounds lighter than their corn-fed counterparts, and sources say Mangurian ordered a number of his athletes to lose 50 to 60 pounds.

“It does have an effect on your confidence when you’re smaller,” one player said. “He’s teaching to be healthy. Most other coaches will have you fill up on burgers and shakes.”

But not everyone agrees that drastic weight loss is safe.

One parent told The Post that Mangurian “assumes that he’s dealing with paid, professional football players” and doesn’t give them proper instruction.

“The players burn a large amount of calories and are not necessarily allowed to replace them,” the parent said. “I don’t think they have much guidance with this.

“At one point in the spring, my son told me that they were out in the freezing cold practicing, all emaciated from the weight loss. He said they looked like a bunch of refugees in a prison camp.”

Rich Forzani, a ’66 graduate and former player, said the parent of another player told him his son lost 30 pounds over the summer and passed out in the bathroom.

Forzani is teaming up with Novak and 65 other alums for the Committee for Athletic Excellence at Columbia — which officially formed last week and is demanding the university fire both Mangurian and athletic director Dianne Murphy.

The group has butted heads with Columbia president Lee Bollinger this season in a series of heated letters to the Columbia Spectator.

Mangurian, 58, was hired in December 2011 after being fired as an assistant by the Tampa Bay Buccaneers. He spent more than a decade in the NFL, including a stint as offensive-line coach with the New York Giants in the ’90s.

Back then, center Brian Williams reportedly clashed with Mangurian because the coach criticized players for being overweight.

In January 2013, Lions staff released an update on Mangurian’s efforts to make players “lean and mean.”

“We are already making significant progress,” they wrote. “From . . . last summer to the end of the season, we saw our players improve their lean muscle mass and decrease their body fat.”

What's Your Take?

The team lost all 10 games this season by an average of 40-7, and there were numerous injuries on both sides of the ball. Mangurian's system does not even come close to being successful, even in a league where there is relative parity because of the high academic quality of all athletes in the Ivy League. Columbia's players are demoralized, as is to be expected.

Mangurian must be replaced, and AD Dianne Murphy shows terrible judgment by standing behind Mangurian without reservation and even criticizing alumni for voicing their concerns.

Accountability does not exist within the Columbia athletic department right now, and it is a group of 100 outstanding student-athletes who are suffering as a result. Shame on Mangurian and Murphy--and University President Lee Bollinger, if he lets this situation fester.